This is a good point that there are more complexities around it than simply going for a walk.

My T seemed a little uncertain when offering me an outdoor session at the coffee shop, as he said I tend to cry during therapy and he was concerned I'd be uncomfortable if I got emotional while in public (I managed to not cry each time, but also didn't go into certain topics that deeply).

He also warned me that it would likely feel different, that it was a sort of "social session." And it did feel like something in between having a therapy session and having coffee with a friend. In part because also disclosed more than usual the first session (I imagine it felt more social to him, too), though less so the other two.

For me, it felt nice having a more casual therapy session like that a few times (plus it enabled me to meet with him in person at a time when he wasn't allowing in-office visits--the first time we met outside, it had been over a year since I'd seen him in person). But I also see how it's potentially risky--for example, if we'd met outside frequently and it started feeling too friend-like. Or if I opted to meet outside regularly in a conscious or subconscious attempt to avoid deeper topics or letting myself get emotional.

So just a couple things to consider and that your T could be thinking about. Maybe he's concerned there are potential risks he's hasn't considered, and that's why he wants to take a course, just to be as careful as possible? Though I understand how the caution can be frustrating.